fewer和less的区别在于：fewer是形容词few的比较级，后面接可数名词复数； less是形容词little的比较级，后面接不可数名词。
比如：
I received less money than the others did. 我比别人收到的钱少.
Now I have fewer friends than before. 现在我的朋友比以前少了。
详细解释：
英 ['fjuːə] 美 ['fjʊɚ]
adj. 较少的
pron. 较少数
int. 较少数
英 [les] 美 [lɛs]
adv. 较少地；较小地；更小地
adj. 较少的；较小的
prep. 减去
n. 较少；较小
n. (Less)人名；(德、意、匈、芬)莱斯
fewer双语例句
1. Officials hoped admitting fewer foreigners would calm the situation.
官员们希望通过减少外国人入境的数量来使局势平定下来。
2. Fewer than 7% of asylum seekers are accepted as political refugees.
寻求避难者中有不到7%的人被视作政治难民。
3. The government says fewer Americans are carpooling to work.
政府称拼车上班的人渐渐少了。
4. Women once again are having fewer children and spacing them further apart.
女人再次减少了生孩子的数量，而且生育之间相隔的时间也更长了。
5. The report shows that fewer couples are getting hitched.
报告显示，结婚的人数呈下降趋势。
less双语例句
1. These files have been zipped up to take up less disk space.
这些文档已经进行了压缩，以节省磁盘空间。
2. He is lined up for no less than four US television interviews.
多达4家美国电视媒体排期邀请他上节目接受采访。
3. Other amenities, less commonly available, include a library and exercise room.
还有一些不太常有的设施，包括图书馆和健身房。
4. His team-mates opened hotel windows, shouting "Jump!" and somewhat less printable banter.
他的队友打开了酒店的窗户，大叫着“跳！”，还开了一些上不了台面的玩笑。
5. They wanted me to change the title to something less gratuitously offensive.
他们希望我将题目修改一下，以免显得太过冒犯。